The present invention relates to a weather strip attached to a door panel of an automobile by an attaching means except for a retainer. The present invention also relates to a weather strip fixed to a door panel of an automobile by a clip, and having a waterproof sponge member, which is attached to the base bottom portion, for ensuring watertightness of the door panel at the base bottom portion. The present invention also relates to a weather strip which is attached to a door panel of an automobile by an attaching means except for a retainer and on the lower face of the base portion of which a seal member closely coming into contact with the door panel is arranged.
Referring to FIGS. 4 and 5 (or FIGS. 8 and 9), a conventional technique is explained below. A door weather strip 170 (260) for automobile use is mostly attached by a retainer 171 (221) mounted on a door panel 130 (220). However, in this case, in order to ensure the sealability between the retainer 171 (221) and the door panel 130 (220), a connecting portion to connect the retainer 171 (221) with the door panel 130 (220) is coated with sealant 172 (222). Accordingly, the weather strip 170 (260) and the sealant 172 (222) interfere with each other. Therefore, the conventional technique has a problem that the sealability of this connecting portion can not be stabilized. Further, at an end portion of the retainer 171 (221), a step portion is created between the retainer 171 (221) and the door panel 130 (220) corresponding to the thickness of the retainer 171 (221). Accordingly, the sealability of this portion is deteriorated. For the above reasons, when importance is placed upon maintaining the sealability of the connecting portion to connect the door panel 130 (220) with the weather strip 170 (260), it is not necessarily required to provide the retainer 171 (221).
Instead of a retainer, it is possible to use an adhesive double-coated tape or a clip as a means for attaching a weather strip to a door panel.
As shown in FIGS. 1 and 2, there have been provided a conventional weather strip 70 which include: a base bottom portion 72 attached to a door panel 20; a hollow seal portion 73 to seal between the door panel 20 and the body panel 30; and a seal lip portion 74. This conventional weather strip 70 is fixed to the door panel 20 by not a retainer but a clip 40. In order to enhance the watertightness with respect to the door panel 20, there is provided a waterproof seal 78, which is a water expansion material and contains a corrosion inhibitor for preventing corrosion of metal, all over the attaching base bottom portion 72 as disclosed in Japanese Examined Utility Model Publication No. 6-42920. However, since the water expansion material containing the corrosion inhibitor is a solid material, it is impossible to put a seal upon the door panel 20 sufficiently.
In order to solve the above problems, it can be considered to take countermeasure that a sponge-like waterproof seal member 79 is attached to the entire lower surface of the base bottom portion. However, in the case where the weather strip is attached to the door panel with a clip, waves are created in the direction of length of the weather strip because only the sponge-like waterproof seal member 79 located close to the clip is compressed and deformed. That is, a portion of the weather strip 70 in which the clip 40 is located is attached to the door panel 20 by a stronger force than other portions. Therefore, the sponge-like waterproof seal member 79 is strongly compressed and the height is reduced. A portion in which the clip 40 is not located is attached to the door panel 20 by a weak force and the height of the sponge-like waterproof seal member 79 becomes larger. As a result, the entire shape of the sponge-like waterproof seal member 79 becomes wave-like.
The thus formed waves of the sponge-like waterproof seal member 79 are greatly affected by a reaction force of the sponge-like waterproof seal member 79. That is, in a state in which the weather strip 70 is fixed to the door panel 20 with the clip 40, it is preferable that the sponge-like waterproof seal member 79 is interposed between the lower face of the base bottom portion 72 of the weather strip 70 and the upper face of the door panel 20, and that the wall thickness of the sponge-like waterproof seal member 79 is equally contracted over the entire length. However, the reaction force of the sponge-like waterproof seal member 79 acts, and the portion in which the clip 40 is located is greatly elastically contracted and deformed because the reaction force is weaker than the attaching force of the clip 40. However, the portion in which the clip 40 is not located is not contracted and deformed so much by the attaching force of the clip 40. Therefore, the base bottom portion 72 of the weather strip 70 is pushed up by the reaction force. As a result, waves are created on the weather strip 70.
Since this conventional sponge-like waterproof seal member 79 is arranged between the base bottom portion 72 of the weather strip 70 and the door panel 20, the wall thickness of the seal member 79 is set at a small value. Therefore, a quantity of elastic deformation of contraction is small. Accordingly, when a force, the intensity of which is higher than a predetermined value, is given, a strong reaction force is generated, and waves tend to be created on the weather strip 70. As a result, watertightness between the weather strip 70 and the door panel 20 is deteriorated and further appearance is deteriorated.
On the other hand, in order to attach the weather strip 170 (260), to the door panel 130 (220) by the above means, it is necessary to stabilize the sealability between the lower face of a base portion (261) and the door panel 130 (220).
From the above viewpoints, a technique by which a highly expanded sponge member is arranged on a lower face of a base portion of a weather strip has been proposed. In the extrusion-molded portion of the weather strip, this highly expanded sponge member is integrally molded by extrusion at the cutout step portion formed on the lower face of the base portion of the extrusion-molded portion. In the die-molded portion, a separate highly expanded sponge member is made to adhere to the lower face of the flat base portion by a post-processing. The specific gravity of the highly expanded sponge member, which is integrally formed by extrusion molding, is usually 0.1 to 0.3, and the specific gravity of the highly expanded sponge member, which is formed separately and made to adhere to the die-molded portion, is usually 0.05 to 0.2.
However, in the die-molded portion, the separate highly expanded sponge member is made to adhere to the lower face of the base portion, which is a flat face. Therefore, it is impossible to set the thickness of the highly expanded sponge member at a high value. Since elasticity of a thin highly expanded sponge member is low, it tends to be plastically deformed, and it is impossible to stably keep the sealability over a long period of time. As a result, in one weather strip, the sealability is high in the extrusion-molded portion, however, the sealability is low in the die-molded portion, that is, it is impossible to exhibit a high sealability over the entire weather strip.
Since the lower face of the base portion of the die-molded portion and the separate highly expanded sponge member are made to adhere to each other on their flat faces, the area of adhesion is not necessarily sufficiently large. When the door is repeatedly opened and closed over a long period of time, the separate highly expanded sponge member slips out from the predetermined position and the sealability is lowered.
The present invention is to solve the above-described problems.
Accordingly, an object of the present invention is to provide a retainerless weather strip which does not causes waves due to the difference in an attaching force even when fixed by a clip and which thus is excellent in watertightness and appearance.
Another object of the present invention is to provide a retainerless weather strip which has a sufficiently high sealability between a lower face of a base portion of a die-molded portion and a door panel.
A still other object of the present invention is to provide a retainerless weather strip which has a sufficient adhesion area between a lower end face of a base portion of a die-molded portion and a highly expanded sponge member.
A still other object of the present invention is to provide a retainerless weather strip which has a stable sealability, over the entire weather strip, continuing from an extrusion-molded portion to a die-molded portion.
The other objects and effects of the present invention will become apparent from the following description.
The above objects of the present invention have been achieved by providing the following retainerless weather strips.
That is, in a first aspect, the present invention relates to a retainerless weather strip to be fixed to a door panel of an automobile by a clip, which comprises:
a base bottom portion to be attached to the door panel;
a hollow seal portion to seal between the door panel and a body panel; and
a seal lip portion,
wherein the base bottom portion has a cutout-shaped step portion formed at a lower end portion on the automobile exterior side of the base bottom portion, and the weather strip further comprises a thick waterproof sponge member provided on the cutout-shaped step portion,
wherein the thick waterproof sponge member has a thickness sufficiently larger than the depth of the cutout-shaped step portion, and has an elasticity such that a portion in which the clip is located and portions in which the clip is not located can be equally elastically contracted when the base bottom portion is fixed to the door panel by the clip so that watertightness is kept between the thick waterproof sponge member and the door panel.
In a second aspect, the present invention relates to a retainerless weather strip to be attached to a door panel of an automobile by an attaching means except for a retainer, which comprises:
an extrusion-molded portion including a base portion having a cutout: step portion formed on a lower face of the base portion of the extrusion-molded portion;
a highly expanded sponge member integrally provided on the cutout step portion by means of coextrusion molding;
a die-molded portion including a base portion having a step cut portion, which continues to the cutout step portion of the extrusion-molded portion, formed on a lower face of the base portion of a die-molded portion; and
a highly expanded sponge member provided on the step cut portion.
In a third aspect, the present invention relates to a retainerless weather strip to be attached to a door panel of an automobile by an attaching means except for a retainer, which comprises:
an extrusion-molded portion including a base portion, wherein the extrusion-molded portion has a cutout-molded portion at a predetermined portion thereof, in which the extrusion-molded portion is cutout remaining the base portion;
a highly expanded sponge member integrally provided along an automobile exterior side edge on a lower face of the base portion of an extrusion-molded portion by means of coextrusion molding; and
a die-molded portion formed by means of die molding and integrated with the cutout portion.